Re: [PATCH v2] ARC: update definitions in elf/elf.h

[Adhemerval Zanella Netto via Libc-alpha <libc-alpha@sourceware.org>]

On 21/11/22 10:06, Shahab Vahedi via Libc-alpha wrote:
> While porting ARCv2 to elfutils [1], it was brought up that the
> necessary changes to the project's libelf/elf.h must come from
> glibc, because they sync it from glibc [2].  Therefore, this patch
> is to update ARC entries in elf/elf.h.
> 
> The majority of the update is about adding new definitions,
> specially for the relocations.  However, there is one rename, one
> deletion, and one change:
> 
> - R_ARC_JUMP_SLOT renamed to R_ARC_JMP_SLOT to match binutils.
> - R_ARC_B26 removed because it is unused and deprecated.
> - R_ARC_TLS_DTPOFF_S9 changed from 0x4a to the correct value 0x49.
> 
> [1]
> https://sourceware.org/pipermail/elfutils-devel/2022q4/005530.html
> 
> [2]
> https://sourceware.org/pipermail/elfutils-devel/2022q4/005548.html
> 
> Signed-off-by: Shahab Vahedi <shahab@synopsys.com>

We discussed this briefly on glibc patchwork review meeting [1],
and if does not trigger any regression it ok to arch maintainers
to handle such changes.

[1] https://sourceware.org/glibc/wiki/PatchworkReviewMeetings

> ---
> Chagelog:
> v2:
>   - Rename instances of R_ARC_JUMP_SLOT to R_ARC_JMP_SLOT.
>   - Remove an unnecessary extra empty line introduced in elf/elf.h.
> 
>  elf/elf.h                | 29 ++++++++++++++++++++++++-----
>  sysdeps/arc/dl-machine.h |  8 ++++----
>  2 files changed, 28 insertions(+), 9 deletions(-)
> 
> diff --git a/elf/elf.h b/elf/elf.h
> index 920e6891e6..da41bad34b 100644
> --- a/elf/elf.h
> +++ b/elf/elf.h
> @@ -4159,6 +4159,15 @@ enum
>  #define R_LARCH_GNU_VTINHERIT  57
>  #define R_LARCH_GNU_VTENTRY  58
>  
> +/* ARC specific declarations.  */
> +
> +/* Processor specific flags for the Ehdr e_flags field.  */
> +#define EF_ARC_MACH_MSK	    0x000000ff
> +#define EF_ARC_OSABI_MSK    0x00000f00
> +#define EF_ARC_ALL_MSK	    (EF_ARC_MACH_MSK | EF_ARC_OSABI_MSK)
> +
> +/* Processor specific values for the Shdr sh_type field.  */
> +#define SHT_ARC_ATTRIBUTES	(SHT_LOPROC + 1) /* ARC attributes section.  */
>  
>  /* ARCompact/ARCv2 specific relocs.  */
>  #define R_ARC_NONE		0x0
> @@ -4166,7 +4175,7 @@ enum
>  #define R_ARC_16		0x2
>  #define R_ARC_24		0x3
>  #define R_ARC_32		0x4
> -#define R_ARC_B26		0x5
> +
>  #define R_ARC_B22_PCREL		0x6
>  #define R_ARC_H30		0x7
>  #define R_ARC_N8		0x8
> @@ -4206,16 +4215,23 @@ enum
>  #define R_ARC_SECTOFF_ME_2	0x2A
>  #define R_ARC_SECTOFF_1		0x2B
>  #define R_ARC_SECTOFF_2		0x2C
> +#define R_ARC_SDA_12		0x2D
> +#define R_ARC_SDA16_ST2		0x30
> +#define R_ARC_32_PCREL		0x31
>  #define R_ARC_PC32		0x32
>  #define R_ARC_GOTPC32		0x33
>  #define R_ARC_PLT32		0x34
>  #define R_ARC_COPY		0x35
>  #define R_ARC_GLOB_DAT		0x36
> -#define R_ARC_JUMP_SLOT		0x37
> +#define R_ARC_JMP_SLOT		0x37
>  #define R_ARC_RELATIVE		0x38
>  #define R_ARC_GOTOFF		0x39
>  #define R_ARC_GOTPC		0x3A
>  #define R_ARC_GOT32		0x3B
> +#define R_ARC_S21W_PCREL_PLT	0x3C
> +#define R_ARC_S25H_PCREL_PLT	0x3D
> +
> +#define R_ARC_JLI_SECTOFF	0x3F
>  
>  #define R_ARC_TLS_DTPMOD	0x42
>  #define R_ARC_TLS_DTPOFF	0x43
> @@ -4224,9 +4240,12 @@ enum
>  #define R_ARC_TLS_GD_LD	        0x46
>  #define R_ARC_TLS_GD_CALL	0x47
>  #define R_ARC_TLS_IE_GOT	0x48
> -#define R_ARC_TLS_DTPOFF_S9	0x4a
> -#define R_ARC_TLS_LE_S9		0x4a
> -#define R_ARC_TLS_LE_32		0x4b
> +#define R_ARC_TLS_DTPOFF_S9	0x49
> +#define R_ARC_TLS_LE_S9		0x4A
> +#define R_ARC_TLS_LE_32		0x4B
> +#define R_ARC_S25W_PCREL_PLT	0x4C
> +#define R_ARC_S21H_PCREL_PLT	0x4D
> +#define R_ARC_NPS_CMEM16	0x4E
>  
>  /* OpenRISC 1000 specific relocs.  */
>  #define R_OR1K_NONE		0
> diff --git a/sysdeps/arc/dl-machine.h b/sysdeps/arc/dl-machine.h
> index c6ad232384..8420cd0006 100644
> --- a/sysdeps/arc/dl-machine.h
> +++ b/sysdeps/arc/dl-machine.h
> @@ -183,14 +183,14 @@ __start:								\n\
>     ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
>     of the main executable's symbols, as for a COPY reloc.  */
>  #define elf_machine_type_class(type)				\
> -  ((((type) == R_ARC_JUMP_SLOT					\
> +  ((((type) == R_ARC_JMP_SLOT					\
>       || (type) == R_ARC_TLS_DTPMOD				\
>       || (type) == R_ARC_TLS_DTPOFF				\
>       || (type) == R_ARC_TLS_TPOFF) * ELF_RTYPE_CLASS_PLT)	\
>     | (((type) == R_ARC_COPY) * ELF_RTYPE_CLASS_COPY))
>  
>  /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
> -#define ELF_MACHINE_JMP_SLOT  R_ARC_JUMP_SLOT
> +#define ELF_MACHINE_JMP_SLOT  R_ARC_JMP_SLOT
>  
>  /* Fixup a PLT entry to bounce directly to the function at VALUE.  */
>  
> @@ -261,7 +261,7 @@ elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
>            break;
>  
>          case R_ARC_GLOB_DAT:
> -        case R_ARC_JUMP_SLOT:
> +        case R_ARC_JMP_SLOT:
>              *reloc_addr = value;
>            break;
>  
> @@ -321,7 +321,7 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
>    ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
>    const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);
>  
> -  if (r_type == R_ARC_JUMP_SLOT)
> +  if (r_type == R_ARC_JMP_SLOT)
>      *reloc_addr += l_addr;
>    else
>      _dl_reloc_bad_type (map, r_type, 1);